Published March 31, 2023
Prescription medicines treat many different illnesses and conditions. Sometimes a person may need to take medicine for a short time (several days) until the condition is resolved. For example, a healthcare provider may prescribe an antibiotic to treat a bacterial infection; in this case, the doctor will prescribe only enough medicine to treat the infection. Other times, prescription medicines are used to treat chronic conditions such as depression, heart disease, or diabetes. These prescription medicines will need to be taken for a long period of time (several months) or possibly for the rest of your life. In this situation, your doctor will order a certain dosage of the medicine to start. However, the dose may need to be adjusted over time.
There are several reasons the dose of medicine may change. For example, medicines such as antidepressants may require a gradual increase in the dose to be effective. Or the dose of a medicine may need to be decreased due to unpleasant side effects. Also, some medicines are dosed based on the person’s weight or laboratory results. Therefore, a change in weight or an abnormal laboratory result can indicate a dose change is needed.
Unfortunately, even though a doctor provides a new prescription with the correct dose, we sometimes learn of pharmacy dispensing errors in which the old dose of medicine is dispensed. This happens when the order for the older dose has not been discontinued in the pharmacy computer system. This can result in a potentially dangerous situation. A few examples are provided below:
Case 1: A 4-month-old infant with a heart condition was prescribed propranolol with instructions for the parents to give 0.8 mL every 6 hours. During a follow-up visit, the doctor increased the dose to 1.3 mL every 6 hours because of the infant’s growth and weight gain. The doctor sent the new prescription electronically to the pharmacy. The parents gave their child 1.3 mL every 6 hours. However, when a refill was needed, a pharmacist filled the prescription using the original prescription, which was still active in the pharmacy computer system. Luckily, the parents caught the mistake and returned the medicine to the pharmacy so the correct dosage instructions could be put on the medicine label.
Case 2: A doctor prescribed Trulicity (dulaglutide) 3 mg for a person with diabetes. But when they requested a refill one month later, the pharmacy dispensed a previously discontinued, and now incorrect, dose (1.5 mg) of the medicine. The pharmacist was not aware that the older dose had been discontinued, since it was still listed in the computer system. When the person asked for a refill, the pharmacist saw the older dose and refilled the medicine using the older active prescription in error.
Here’s what you can do: Consider the following recommendations to prevent errors when your doctor prescribes a dose of medicine that is different from what you have been taking.